A Study On The Characteristics And Optimization Of A New Type Heat-Source Tower With Air Pretreatment Function

As a new efficient cold and heat source scheme in building, heat-source tower heat pump system has a high application prospect.However, when inlet air’s vapor pressure is greater than solution’s, the moisture will transmit from air into solution and the freezing point of solution increases, which will affect the safety of system. Currently, adding solute or regeneration of solution is mostly used to solve this problem, but which will increase energy consumption and cost, and impact unit performance. Aiming at this problem, a new type heat-source tower structure with air pretreatment function is put forward. Simulation and experiment are performed to study on its characteristics and optimization:Mathematical model of crossflow tower and coil are established, in order to form mathematical model of new type tower. A comparative study has been conducted to investigate the effect of atmospheric humidity, inlet solution temperature, mass flow of air and solution on heat-mass characteristic between new type tower and ordinary tower. Results indicate that under the same operating parameters, new type tower has better heat transfer characteristics and weaker moisture absorption properties (or better regeneration ability), so that it can achieve self-balancing in the running process of the system more easily. With decreasing exposure humidity and increasing inlet solution temperature, their heat and mass exchange amounts are reduced. With increasing mass flow solution and air, their heat exchange amounts are reduced, but their mass exchange amounts are related to environment conditions. Under higher humidity condition, proper reducing mass flow of solution and air is helpful to reduce moisture absorption amount of solution. Under lower humidity condition and liquid regeneration, proper improving air mass flow contributes to liquid regeneration.Mathematical model of heat-source tower heat pump system is established. Under the same heating load, a comparative simulation study has been conducted to investigate the effect of atmospheric temperature and humidity on unit performance and mass characteristic between new type tower heat pump system and ordinary tower heat pump system. During system operation, with increasing exposure temperature or humidity, their unit COP and moisture absorption quantity rise. Under the same condition, adoption of new type tower can improve unit performance slightly, but reduce moisture absorption apparently.New type tower experiment table was built.Experiment studies on new type tower and ordinary tower’s operation characteristics under different inlet solution temperature, mass flow of air and solution were done.Their unit performance and mass characteristic during the running of the system are studied. Results showed that the new type heat pump system’s heating capacity and COP is slightly better than the ordinary tower, but reduce moisture absorption apparently.